mm/huge_memory.c in the Linux kernel before 2.6.38-rc5 does not prevent creation of a transparent huge page (THP) during the existence of a temporary stack for an exec system call, which allows local users to cause a denial of service (memory consumption) or possibly have unspecified other impact via a crafted application.
https://exchange.xforce.ibmcloud.com/vulnerabilities/65535
https://bugzilla.redhat.com/show_bug.cgi?id=678209
http://www.securityfocus.com/bid/46442
http://openwall.com/lists/oss-security/2011/02/17/6